Dust separator



Filed Nov. 24, 19:51 2 l5 Avvaw 70R- W /71 EMA 0!)? Patented May 29, 1934 UNITED STATES PATENT OFFICE.

Application November 24, 1931, Serial No. 577,125 In Great Britain September 24, 1931 3 Claims. (Cl. 183-85) The invention relates to dust separators in which steam, gas or vapour has a rotary motion in a separating or vortex chamber and by the action of centrifugal force suspended impurities,

5 whether liquid or solid, are thrown out to the sides of the separator.

In the following description the term separator is-intended to include vortical apparatus of the type and for the purpose indicated; the term gas is intended to include any gas or vapour as well as steam; and the term dust is intended to include any impurities to be removed from the gas".

The invention has for its object to provide a simple construction of dust separator of this type having high efliciency.

structurally the separator is constituted by a substantially cylindrical upright casing free from internal vanes and comprising an admission chamber, a separating chamber proper and a dust settling chamber in substantially coaxial and superposed relation. The high efiiciency is obtained by providing at the upper end of the casing a gas admission chamber in which the gas is given a rotary motion prior to its entry to.

the separating chamber proper through a convergent annular-vaneless passage to the separating chamber wherein the gas has a true free vortex motion as distinctirom mere rotary motion, by the provision of a dust settling chamber situated below, shielded from, but in fluid communication with the separating chamber, and by the provision of a gas discharge pipe extending from a point at about the axis of the separating chamber, the pipe in some cases having a flange or lip at or near its inner end.

In the accompanying drawing Fig. 1 is a sectional elevation of a down-flow separator, that is one having a descending gas discharge pipe.

Fig. 2 is a sectional planon the line AA of Fig. 1.

Fig. 3 is a part sectional elevation showing a modified form of the lower part of a separator of the type shown in Fig. 1.

Referring to the figures, 1 denotes the cylindrical casing of the separator, 2 is the skew or tangential gas passage or'passages by which gas enters the admission chamber 3 whereby rotary flow is set up therein. A conical deflector 4 sub- 50 stantially coaxial with the casing partially .iso-

lates the admission chamber 3 from the separating chamber 5 and permits fluid communication between these chambers through the annular vaneless passage '1 between the deflector 4 and 55 the wall of the casing 1, which passage is convergent downwards and has its minimum width 6 at or near the lower edge of the deflector 4. The deflector 4 is rigidly connected to the casing 1 by means of the piece 15.

The inner end of the gas discharge passage or 6 pipe 8 projects inwards into the separating chamber 5. This pipe 8 may be fitted with a flange or lip 9 at or near its inner end. Instead of having a straight section as shown, the flange may have a bent or curved section.

The dust chamber 10 is partially isolated from the separating chamber 5 by means of the conical diaphragm 11 which is substantially coaxial with the casing 1 and which allows fluid communication between the chambers 5 and 10 through the substantially annular passage 12 at the edge of the diaphragm. 13 denotes the dust outlet. The diaphragm 11 may be fixed in position by its rigid attachment to the gas discharge pipe as shown in Figs. 1 and 3, or by other com venient means.

In Fig. 3 the diaphragm 11, besides partially isolating the separating chamber 5 from the dust chamber 10, may be considered as constituting and replacing the flange 9 (Fig. 1) of the gas discharge pipe 8.

The rotary motion of the gas leaving the admission chamber 5 resulting from the skew or tangential disposition of the inlet or inlets 2 persists in the vortex or separating chamber 5 wherein the gas motion becomes of true vorticalcharacter, the flow being inwards to the coaxial or nearly coaxial gas discharge pipe 8 of less diameter. In the admission chamber 3, on the other hand, the gas motion is merely rotary, and not of the character of a free vortex, because the circular flow of gas to the annular vaneless outlet. 7 does not converge to a diameter less than the general rotary flow in the admission chamber. Nevertheless, the flow in the chamber 3 converges to the narrow width of the outlet '7 and, because of this convergence, the flow is rendered of streamline nature or eddyless, such kind of flow being also maintained in the separating chamber because of convergence of flow to the discharge pipe 8. Because of the absence of eddies, which are inimical to separation, and because of the centrifugal force having a greater efiect on the suspended relatively dense dust than on the gas, the dust is impelledout to the sides of the separating chamber and descends by gravity through the annular passage 12 into the dust chamber 10 where it settles to the outlet 13.

By dispensing with vanes in the annular passage 7, the shape of the stream lines of the gas 110 the annular passage 'lrequire to move outwards through the radial width of the passage in order to reach the sides of the casing and to be separated, it is an advantage to have the-annular passage oi small radial width in order to ensure as early a separation as possible in the separating chamber.

By providing the flange or lip 9 on the inner end of the gas discharge pipe (which has already been proposed in separators having vanes between an admission chamber with axial gas admission and a vertical separating chamber) the component of gas flow along the outer surface of the discharge pipe 8 is minimized and separation is thus improved.

The edgeof the diaphragm 11 being close to the casing, the dust chamber 10 is shielded from the high velocity gas in the separating chamber so that the gas in the dust chamber is comparatively quiescent, permitting easy settlement of the dust therein towards the dust outlet 13.

What I claim is:-

1. A dust separator comprising a substantially cylindrical casing including an upper gas admission chamber internally unobstructed and bounded circumferentially by the side wall of said casing, an intermediate separating chamber constructed to permit free vertical movement of gas within said intermediate chamber, and a lower dust settling chamber of inverted conical form,'

said three chambers being in substantially coaxial and superposed relation, at least one external gas supply pipe disposed in nonradial relation to the axis 01 said casing for leading gas to said admission chamber with a tangential component oi. motion, an imperforate gas outlet pipe having its inner end disposed coaxially with said chambers and open at said end to said intermediate chamber, the open end of said gas outlet pipe receiving the whole of the gas directly from said intermediate chamber, a deflector oi erect conical shape partially isolating said admission chamber from said intermediate chamber, said deflector bounding one side of a circumferential annular gas inlet to said intermediate chamber from said admission chamber, said annular inlet converging from a point at the level oi. said gas supply pipe, and an imperi'orate partition of erect conical form fixed to the inner end of said gas outlet pipe and disposed coaxially with said gas outlet pipe between said intermediate chamber and said dust settling chamber, aflording between an edge of said partition and the inner wall of said casing a radially narrow annular passage for the transfer of dust from said intermediate chamber to said dust settling chamber, said partition 

